The following is a collection of various artist's music used at gigs from the years: '91 - '09. Now with static links - peruse the tracks at your leisure and download what you want or have the whole thing as a zip. This may well be something I carry forward myself in to more recent gigs - time...
I'm guessing if it was played prior to gigs, it's probably something he'd have listened to.
The Sex Pistol formed in 1975 and by 1978 they had split up. This time-frame is what most people consider as Punk. The Clash for example formed in 1976. Morrissey particularly liked bands/acts such as Television, Patti Smith, and the Ramones (NY based acts) from this period and perhaps less so the Sex Pistols, the Clash, and the Damned (from the UK). Iggy Pop and the New York Dolls came before this period but were considered originators of Punk.
Siouxsie and the Banshees were formed right at the very start of the UK Punk movement in 1976 - they were part of the "Bromley Contingent" who helped popularise the music and shaped the fashion in the UK. Their sound did evolve however and they were more successful commercially in the Post-Punk period. Similarly The Fall formed in 1976 although they too were more well known for their Post Punk output. Both bands were Punk bands originally.